Global and Local Impacts of Soil Confinement on RC Pile Nonlinearity

摘要

Greater confinement of the soil foundation may globally reduce the shear span length, which may raise the risk of shear failure of RC piles. On the other hand, soil confinement may improve the flexural ductility of the pile section locally. This study discusses these global and local impacts of soil confinement on the RC-pile mechanistic behaviors, experimentally and analytically. Small-scale mortar-based piles were newly produced as a mockup of real-scale reinforced concrete so as to obtain the consistent nominal shear strength by reducing the shear transfer along cracks to overcome the size effect. Then, the global impact of soil confinement on pile shear failure is reproduced inside the small-scale experimental devices with soil. The soil-pile interaction test also shows the local impact of soil confinement in terms of increasing the flexural ductility of the miniature pile section by suppressing cover spalling and local buckling of reinforcement. It is confirmed that the coupled local and global effects of soil confinement can be consistently taken into account in 3D computational simulation without reducing the degree of freedom for strain fields.